1 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
new file mode 100644
index 0000000000..ba9e4b72d8
--- /dev/null
+++ b/arch/arm/include/asm/atomic.h
@@ -0,0 +1,113 @@
+/*
+ *  linux/include/asm-arm/atomic.h
+ *
+ *  Copyright (c) 1996 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  Changelog:
+ *   27-06-1996	RMK	Created
+ *   13-04-1997	RMK	Made functions atomic!
+ *   07-12-1997	RMK	Upgraded for v2.1.
+ *   26-08-1998	PJB	Added #ifdef __KERNEL__
+ */
+#ifndef __ASM_ARM_ATOMIC_H
+#define __ASM_ARM_ATOMIC_H
+
+#include <linux/config.h>
+
+#ifdef CONFIG_SMP
+#error SMP not supported
+#endif
+
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i)	{ (i) }
+
+#ifdef __KERNEL__
+#include <asm/proc/system.h>
+
+#define atomic_read(v)	((v)->counter)
+#define atomic_set(v,i)	(((v)->counter) = (i))
+
+static inline void atomic_add(int i, volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	v->counter += i;
+	local_irq_restore(flags);
+}
+
+static inline void atomic_sub(int i, volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	v->counter -= i;
+	local_irq_restore(flags);
+}
+
+static inline void atomic_inc(volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	v->counter += 1;
+	local_irq_restore(flags);
+}
+
+static inline void atomic_dec(volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	v->counter -= 1;
+	local_irq_restore(flags);
+}
+
+static inline int atomic_dec_and_test(volatile atomic_t *v)
+{
+	unsigned long flags;
+	int val;
+
+	local_irq_save(flags);
+	val = v->counter;
+	v->counter = val -= 1;
+	local_irq_restore(flags);
+
+	return val == 0;
+}
+
+static inline int atomic_add_negative(int i, volatile atomic_t *v)
+{
+	unsigned long flags;
+	int val;
+
+	local_irq_save(flags);
+	val = v->counter;
+	v->counter = val += i;
+	local_irq_restore(flags);
+
+	return val < 0;
+}
+
+static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	*addr &= ~mask;
+	local_irq_restore(flags);
+}
+
+/* Atomic operations are already serializing on ARM */
+#define smp_mb__before_atomic_dec()	barrier()
+#define smp_mb__after_atomic_dec()	barrier()
+#define smp_mb__before_atomic_inc()	barrier()
+#define smp_mb__after_atomic_inc()	barrier()
+
+#endif
+#endif